Pneumatic devices which may be manually operated by compression by a person's hand or foot are well known to those skilled in the art.
In 1909, in his U.S. Pat. No. 926,315, Fritz Beck disclosed a pneumatic device comprised of a compressible ball mounted in a holder provided with two air passages; when air was to be forced out of the device, the operator had to place a finger over one of the air passages while compressing the ball with his thumb. Beck's device presented several problems. In the first place, it required a substantial degree of manual dexterity for the operator to simultaneously seal the intake air passage and compress the ball with his thumb. In the second place, it required a relatively large amount of force (and strength) to deliver a relatively small amount of air from the device In the third place, the device was relatively bulky and could not be compressed so that it would take up a relatively small amount of storage space.
The problem of providing an inflation device which would deliver a reasonable quantity of air at moderate pressure had not been solved by 1929. In his U.S. Pat. No. 1,787,153, William H. Huffman described a device which was capable of delivering large quantities of air at low pressure for the purpose of inflating air mattresses, pneumatic boats, and similar devices. In column 1 of his patent, Huffman disclosed that the prior art devices required ". . . a great amount of manual labor and exertion . . ." and were ". . . slow in process .. ." and ". . . cumbersome to handle . . ." Huffman's solution was to provide a refillable, pliable container with one open end which was designed to be ". . . held at arm's length to the wind . . ." and operated with ". . . a quick scooping action . . ." to fill it with air. Once Huffman's device had been filled with air, the open end was sealed and then rolled up in order to discharge the air. There are several disadvantages to Huffman's approach. In the first place, his device is cumbersome to use (especially in a restricted space) and difficult to discharge air from; furthermore, the rate of air discharge from the device is relatively slow.
Another inflation device which required a fair amount of manual dexterity to operate was disclosed in 1937 in Salvatore Scavo's U.S. Pat. No. 2,094,499. The life preserver described in this contained a bulb having an air inlet opening. In order to discharge air from the bulb, the operator placed a finger over the opening and compressed the bulb by squeezing. This device Was no less disadvantageous than the device disclosed in the Beck patent.
In 1952 yet another inflation device was described in U.S. Pat. No. 2,686,006 of Hasselquist. The device of this patent was comprised of a hollow body having a plurality of axially-expansible annular folds In order to operate this bellows-like structure, one first had to manually extend the bellows with both hands to draw air therein. Thereafter, the bellows was compressed to discharge the air. This device required a substantial amount of upper body strength and the use of both hands to operate.
The inflation devices provided prior to 1955 apparently were not suitable for use by children. In his 1955 patent, paul Glasco disclosed that "At the present time there is lacking a satisfactory balloon pump with which small children may quickly and easily blow up balloons and other inflatable devices." However, the device provided by Glasco was not entirely satisfactory for use by children. This device, which was comprised of a hollow body with an exhaust valve and an intake valve, required the child to place his thumb over the intake valve while squeezing the ball. In addition to requiring a fair amount of manual dexterity from the child, it also required a substantial amount of strength to deliver only a relatively low volume of air.
In 1964, Louis Mirando disclosed a foam-filled pump in his U.S. Pat. No. 3,133,696. Mirando disclosed that, prior to using his pump, ". . . the valve 27 provided on the mattress is first closed . . . ;" however, no valve 27 is shown in Mirando's figures. After the valve 27 has been manually closed, one then had to squeeze the foam material in the Mirando device by stepping on it with one's foot. It appears that, in addition to requiring the closure of an intake valve 27, the Mirando device also wasted a substantial amount of energy for the compression of the foam.
In 1967, in his U.S. Pat. No. 3,297,241, Bror Andreasson discussed the problems with the prior art inflation devices. In column 1 of his patent, Andreasson disclosed that the prior art air pumps were ". . . in the shape of bellows or a rubber bulb with a valve." These pumps, according to Andreasson, were ". . . hard to operate . . ." With these pumps, "the inflation is rather tiring and time-wasting due to the small volume which is inflated at each pump stroke." The apparatus of the Andreasson patent, however, required a fair amount of coordiation to operate. This device, which contained a large rectangular bag, a mouth piece arranged in the wall of a chamber of the bag, and a closable valve opening provided in a partition of the bag, required the operator to repeatedly fill the bag with air, manually press most of the air out of the bag, close off an intake valve on a small partition of the bag, and compress this small partition area while keeping the intake valve closed.
In 1968, in his U.S. Pat. No. 3,363,833, Asmund Stavanger disclosed an elastic plastic bag which could be folded in its axial direction to a configuration in which it took up only a fraction of its original volume. However, when the wall portions of the bag of this patent were bent beyond a dead-center position, it became necessary to apply force to return the bag to its expanded, operative position.
It is an object of this invention to provide a low pressure fluid pump which can readily be operated by a child.
It is another object of this invention to provide a low pressure fluid pump which, during its operation, does not require that any of its orifices be sealed by a finger, hand, or other body part of an operator.
It is yet another object of this invention to provide a low pressure fluid pump which, when it is not in use, can be readily compressed to a configuration in which its takes up a space which is only a small fraction of its original volume.
It is yet another object of this invention to provide a low pressure fluid pump which, when it is not in use, can be readily maintained in a compressed configuration.
It is yet another object of this invention to provide a low pressure fluid pump which can be operated with only one hand or other body part.
It is yet another object of this invention to provide a low pressure fluid pump whose operation does not require the expenditure of a substantial amount of energy in compressing a relatively high-density material
It is yet another object of this invention to provide a low pressure fluid pump which, after it has been compressed to deliver fluid from its chamber, rapidly and automatically returns to its operative position.
It is yet another object of this invention to provide a low pressure fluid pump which delivers a relatively large amount of air per compression cycle.
It is yet another object of this invention to provide a low pressure fluid pump comprised of a self-sealing intake valve.
It is yet another object of this invention to provide a low pressure fluid pump with an intake valve which does not extend into the chamber of the pump.
It is yet another object of the invention to provide a low pressure fluid pump which allows the user to compress the pump with at least a major portion of his body weight.
It is yet another object of this invention to provide a low pressure fluid pump which is simple and economical to manufacture.
It is yet another object of this invention to provide an article of manufacture comprised of the low pressure fluid pump of this invention packaged with a multiplicity of balloons.
It is yet another object of this invention to provide a pump apparatus suitable for inflating receptacles requiring medium to high fluid pressure.
It is yet another object of this invention to provide a low pressure fluid pump which is relatively lightweight.
It is yet another object of this invention to provide a low pressure fluid pump at least one of whose interior surfaces provides a uniform surface on which a printed message may appear.